The basic mechanism of skin aging is known to take place in the extracellular matrix, the so-called basal lamella, when situated at the intersection between epithelium and connective tissue. Regeneration of the extracellular matrix is highly important as it considerably influences the behaviour of those cells that are in contact with it, in particular their growth, migration, proliferation, form and functions. An age-related reduction of collagen synthesis by fibroblasts occurs in this extracellular matrix, the consequence of which being a reduced number of chemical substances secreted by these cells. As skin proteins consist by approx. 80% of collagen, already a small natural decrease of the collagen concentration in the tissue may have clear consequences on the mechanical and physiological properties of skin.
Katayama et al. (The Journal of Biological Chemistry, Vol. 268, No. 14, pages 9941-9944, 1993) found that the minimal subfragment sequence for stimulating collagen and fibronectin is represented by the pentapeptide Lys-Thr-Thr-Lys-Ser. Sequences with four amino acids or less have a slighter or no stimulating effect.
The European patent application WO 00/15188 describes the effect of the palmitoylated pentapeptide Palm-Lys-Thr-Thr-Lys-Ser as a component for treating skin aging, accelerating wound healing and improving skin moisturizing.